NEW ORLEANS (CNN) – Progressive leaders gathered at the annual Netroots Nation conference sought to deliver a clear message about the Democratic Party’s direction headed into the 2020 presidential race: They won’t settle for a moderate to take on President Donald Trump.

The three-day gathering of thousands of progressive activists amounted to a rejection of warnings from the Democratic establishment that their calls for single-payer health care, abolishing Immigration and Customs Enforcement agency and other progressive priorities would alienate moderate and Republican voters who are otherwise inclined to vote against Trump — both in November’s midterm elections and in the 2020 presidential primary.

Alexandria Ocasio-Cortez, the 28-year-old Latina who shocked the political establishment when she ousted the No. 4 House Democrat, New York Rep. Joe Crowley, in a primary this summer, urged Democrats to “come home” to ideas that were first proposed by Franklin D. Roosevelt.

“We are picking up where we left off when we were at our most powerful, when we were at our greatest,” she said.

Kevin de León, the California state senate leader who is challenging long-time Democratic Sen. Dianne Feinstein this fall, said progressives are in “a battle for the soul of our nation.”

“Americans across the nation are looking for a new, bold generation of leadership in Washington — warriors,” he said. “Warriors who will fight.”

In speeches, panels and conversations among the 3,000 activists at Netroots Nation, a platform for the progressive wing of the party headed into 2020 crystallized. At its core: A “Medicare-for-all” health care system; tuition-free college and a student debt bailout; a $15-an-hour minimum wage; a federal jobs guarantee; a major overhaul of the nation’s immigration enforcement; and action to address inaccessibly high housing costs.

“Republicans are going to call us socialists no matter what we do. So we might as well give them the real thing,” said Cynthia Nixon, the actress and activist who is challenging New York Gov. Andrew Cuomo in September’s Democratic primary.

Progressives’ calculation that Democrats should reject a centrist approach is partially a result of Trump’s unpopularity, which has resulted in backlash against Republicans in special elections and state-level races over the last year.

The President’s unpopularity has also led to the groundswell of activism — seen through the Women’s March, pro-gun control efforts, the Black Lives Matter movement and more — and interest in non-presidential elections among rank-and-file voters after Democrats watched in agony as their voters sat out eight years of off-year elections.

New York City Mayor Bill de Blasio compared the political environment to 1974, after Richard Nixon had resigned the presidency amid the Watergate scandal. In that year’s midterm elections, Democrats gained 49 seats in the House and four seats in the Senate.

“This is an extraordinary moment,” de Blasio said. “We can’t think of it as, we’re just filling a niche. We have to see ourselves as authors of an emerging majority.”

Doing so, de Blasio said, requires “telling the voices of false pragmatism and phony moderation that we don’t believe their lies.”

“Progressives, it’s our time,” he said.

Buoying progressives’ hopes is that primary voters have favored female candidates over white, male establishment preferences in several key races. And in others — like Kara Eastman’s win in a Nebraska House primary and Ocasio-Cortez’s victory in New York — more liberal candidates have prevailed.

It’s given liberal activists confidence that they can win in the Trump era without sacrificing their political values.

“Swing voters don’t vote for the person who is moderate enough, the person who is most timid, the person who backs down from their starting point,” Ocasio-Cortez said. “The swing voter votes for authenticity.”

She argued that Democrats are wrong to focus on convincing moderates and Republicans to back their candidates and should instead aim to motivate those who sat out previous elections.

The party’s focus should be “not just red to blue, it’s non-voter to voter,” she said. “That’s our swing voter.”

Many of the Democratic 2020 presidential prospects who attended the gathering shied away from other speakers’ calls for insufficiently liberal Democrats to be defeated, instead calling on Democrats to unite against Trump.

But — with a receptive audience — they also made the case for the party to push leftward.

California Sen. Kamala Harris defended a focus on issues of race, gender and sexual orientation — rather than just economics — as “about American identity.” Massachusetts Sen. Elizabeth Warren cast a political system that benefits the rich and corporations over working people as the left’s political enemy. New Jersey Sen. Cory Booker urged Democrats to reject the “normalcy of injustice.”

Even Democrats who might previously have been seen as more moderate and economics-focused, and are weighing 2020 presidential runs, challenged their party to move leftward.

Ohio Rep. Tim Ryan — who opposed abortion rights until January 2015 and represents Youngstown, the sort of blue-collar region that has slipped away from Democrats in recent years — called for an agenda that included marijuana legalization, a student debt bailout, an expansion of Social Security and efforts to reverse the effects of global warming.

Julián Castro, the former Housing and Urban Development secretary, cast Democrats as moving aggressively away from Trump’s “Make America Great Again” slogan.

“You see, as progressives we’re not interested in making our country anything again,” he said. “We’re not looking backward. We’re looking to the future. We’re interested in the future and making America better than it ever has been.”